Question

Number of moles of the solute per kilogram of the solvent is:

• A. mole fraction
• B. molality
• C. molarity
• D. molar mass

Answer 1

The correct option is B molality

Number of moles of the solute per kilogram of the solvent is molality.
$\text{Molality}=\frac{\text{Number of moles of the solute}}{\text{Mass of solvent (in kg)}}$
$\text{Molarity}=\frac{\text{Number of moles of the solute}}{\text{Volume of solution (in L)}}$
$\text{Mole fraction}=\frac{\text{Number of moles of the solute}}{\text{Number of moles of the solute}+\text{Number of moles of the solvent}}$
$\text{Molar mass}=\frac{\text{Mass of substance}}{\text{Number of moles of substance}}$
Hence, the option (B) is the correct answer.